The great Star of Africa or "Cullinan" diamond was found in the year 1905, in the Premier Mine at Pretoria, South Africa, and took its name from Mr. T. M. Cullinan, then one of the chief officials of the mine. It was bought by the Union Government of South Africa, and presented to Edward VII. to be added to the Crown Jewels of the Empire. The rough diamond was cut into four great brilliants and many smaller ones.
The largest portion is drop-shaped, weighs 516 1/2 carats, and measures 2 5-16th inches in length and 1 13- 16th at its broadest part. It is set in the head of the King's Sceptre. The second largest portion is set in the band of the King's State Crown, just below the Black Prince's ruby. The third and fourth portions were set in Queen Mary's Crown.
The early history of the Stuart sapphire is somewhat obscure, though it probably belonged to Charles II. and was certainly amongst the royal Jewels which James II. took with him when he fled to France. From him it passed to his son, Charles Edward, the Old Pretender, who bequeathed it to his son, Henry Bentinck, known later as Cardinal York. The Stuart cause being dead Cardinal York left the sapphire with other Stuart relics, to George III.
In Queen Victoria's State Crown this fine jewel occupied a prominent position in the front of the band just below the Black Prince's ruby. This pride of place it relinquished in favour of the Star of Africa, and now occupies an exactly opposite setting at the back of the King's State Crown.
The sapphire of St. Edward in the centre of the cross patée on the top of the King's State Crown is held to have been in the Coronation Ring of Edward the Confessor, who ascended the Throne in 1042. How the stone and ring passed through the deplorable devastation of the Commonwealth is not clear, but a small article of this sort might easily escape unnoticed, hidden, as was the Ampulla, in Westminster Abbey, or concealed by some devoted adherent of the Stuarts. It was supposed in the old days to have the magic power of curing cramp.